[ILUG] yum and apt gurus, please read

[Paul Jakma]

On Mon, 2 May 2005, Philip Trickett (List) wrote:

> Why would that be then?

Yum is *dog* slllloooooooooowwwwww....

# time apt-cache search ^foobar

real    0m2.688s
user    0m1.087s
sys     0m0.554s

# time yum -C search ^foobar
Searching Packages:
Setting up repositories
Reading repository metadata in from local files
No Matches found

real    0m7.694s
user    0m5.810s
sys     0m0.620s

If we try again, but searching for '^foo' (which should match a few 
things):

# time apt-cache search ^foo
Omni-foomatic - Foomatic data for the Omni Print Driver System
foomatic - Foomatic printer database.
foobillard - A 3d 3d billard game for x
foobillard-debuginfo - Debug information for package foobillard

real    0m2.106s
user    0m1.101s
sys     0m0.535s

# time yum -C search ^foo
<snipping non immedaite package-match output>
foomatic.i386                            3.0.2-18 
foomatic-debuginfo.i386                  3.0.2-18 
foobillard.i386                          3.0a-2 
foomatic.i386                            3.0.2-18

real    0m7.211s
user    0m5.730s
sys     0m0.730s

Here's the kicker, in the above examples apt-cache is running on an 
800MHz Athlon and yum on a dual 2.4GHz Xeon box. They both have 
512MB, but the Athlon has PC100 RAM, the Xeon has DDR-333 or 
somewhere around there.

Even better, the apt box has at least 25% more packages to search 
through:

# apt-cache stats
Total Package Names : 22026 (881k)
   Normal Packages: 4797
   Pure Virtual Packages: 9200
   Single Virtual Packages: 7347
   Mixed Virtual Packages: 27
   Missing: 655
Total Distinct Versions: 7524 (361k)
Total Dependencies: 102767 (2877k)
Total Ver/File relations: 19056 (305k)
Total Provides Mappings: 32292 (646k)
Total Globbed Strings: 109 (1921)
Total Dependency Version space: 61.7k
Total Slack space: 86.4k
Total Space Accounted for: 5159k

# yum list | wc -l
3498

Finally, yum has some pathological problems in how it does RPM 
upgrades, it essentially does them ala rpm --force, which really 
really sucks if there happens to be a problem somewhere. Apt doesnt 
tell rpm to ignore all its checks. This means apt will on occassion 
bomb out with rpm errors (even though apt's dependency checks said 
the package sohuld be installable), but it means at least its nearly 
always easily recoverable.

Yum OTOH has the potential to make a *serious* mess of your machine. 
(particularly wrt installing i386 packages on x86-64 machines - which 
is how i discovered the joys of yum.. it overwrite glibc bits with 
i386 bits. This was partly due to bad packaging, but it highlighted 
Yum's insane "rpm --force" way of installing packages. Rpm could 
easily have noticed the conflicting files from i386 and x86_64 
packages and aborted before allowing yum to fsck up the machine).

Yum really really sucks imho.

However, it's new and written in python, hence it's flavour of the 
RedHat.. - apt is a huge amount of C++ and apparently the code is a 
bit of a mess and hard to maintain. It's just a shame yum is far 
/worse/ than apt..

regards,
-- 
Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
Fortune:
On a paper submitted by a physicist colleague:

"This isn't right.  This isn't even wrong."
 		-- Wolfgang Pauli